The BU ADC Clinical Core (CC) conducts and enhances cutting-edge Alzheimer?s disease (AD) research. CC registry data and subject participation support local and national clinical research studies. We have successfully maintained approximately 20% African American representation in the registry. The CC obtains research-quality MRI scans on registry participants and CC investigators are actively engaged in, and make major contributions to national and international AD research endeavors, including genetics and genomics, biomarker development, cognitive and functional assessment, and cognitive neuroscience. CC investigators have also made significant contributions to the clinical description, diagnosis, and risk factor analysis of chronic traumatic encephalopathy (CTE). We have fully integrated the examination of CTE, with an emphasis on the comparison of CTE and AD, and have included a cohort of former National Football League (NFL) players in the CC registry. We also have integrated CC activities and methods with those of several funded studies of CTE affiliated with the CC. During the next funding cycle, the CC will have the following specific aims: Aim 1: To evaluate and longitudinally examine a registry of approximately 425 participants, comprised of: 50 cognitively normal controls without subjective cognitive complaints (SCC); 125 controls with SCC; 100 subjects with mild cognitive impairment; 75 subjects with mild-moderate AD dementia; and 75 former NFL players with extensive repetitive head impact exposure. Aim 2: To provide data and a source for well-characterized participants for local and national research studies on brain aging, AD spectrum, and CTE research. Research-quality diagnoses will be made on all participants through multidisciplinary diagnostic consensus conferences. High quality data will be collected and submitted to the National Alzheimer?s Coordinating Center (NACC) for data sharing with qualified investigators. The Registry was designed to meet the recruitment needs of the local and national AD research community. Aim 3: To obtain brain donation consents for a minimum of 75% of registry participants and to work with the Neuropathology Core (NPC) to successfully obtain brain tissue from a minimum of 90% of consented participants upon death. The CC and the NPC will examine clinicopathological agreements, with a special emphasis on the comparison of AD and CTE. Aim 4. To collect blood and CSF products from registry participants. The CC will work closely with the NPC to integrate the collection of specimens with the analysis, banking, and distribution of specimens. We will extract DNA and genotype APOE and provide samples to qualified AD and CTE researchers, the National Cell Repository for Alzheimer?s Disease and the Alzheimer?s Disease Genetics Consortium. Aim 5: To conduct research-quality MRI scans on a minimum of 85% of the registry to support AD- and CTE-related research. We will upload MRI data to NACC. The Neuroimaging section of the CC will conduct post-processing of scans and will make the data available to CC investigators and to others in the AD and CTE research communities.